Electrical fitting



Oct. 4, 1932. a'. A. JOHNSON ELECTRICAL FITTING Original Filed May 1'7,1928 ZSheets-Sheet 1 INVENTOR GEORGE A. JOHNSON {y 722.; arz-zarrzeys'Oct. 4, 1932.

G. A. JOHNSON 1,881,318

ELECTRICAL FITTING I Original Filed May 17, 1928 2 Sheets-Sheet 2 I 5;41/ L|1 i k [a INVENTOR GEORGE A. JOHNSON 5 25 az'zarne ys Patented Oct.4, 1932 UNI'IPED STATES PATENT orslca GEORGE A. JOHNSON, OF FAIBEIELD,CONNECTICUT, ASSIGNOR TO THE BRYAN T BEE?- TBIC COMPANY, OF BBIDGEPORT,CONNECTICUT, A CORPORATION' OF CONNECTICUT ELECTRICAL FITTING Originalapplication filed m 17, 1928,

Serial K0. 278,447. Divided and this application filed January 8,

1930. Serial no. 4193,51.

This'application is a division of my application Serial Numbef 278,447filed May 17, 1928. The invention herein described and claimed has to dowith a simplified construe; tion of the casing for an electric switch orother electrical fitting. One object attained is a simple way ofsecuringa cover on the casing by the members which are used to mount the casing,for instance in an outlet .box,

plate to the casing. The invention also provides a ,way of securingaunitary switch movement in the casing.

In the accompanying drawings- Figure 1 is a top plan view of a switchembodyingthis invention. i

Figure 2 is a view of the same sw tch in side elevation. i

Figure 3 is a view in side elevation with 20, a part at one end brokenaway. 1

Figure 4 is a view in section on the line 4-4 of Figure 3. The switchcomprises thre'e'main parts, the

base 11, the cover 12 and the switch movement. Q The base 11 is ofinsulating material and.

.. has a well for the switch movement. On the corners of the base at theopen endof the well are bosses 14 and, at the mid-portions oi itsopposite ends, larger bosses 15, these bosses serving to position thecover. The inner bottom surface of the base is recessed at 16 to permitrockingof the contact carrier. I At one end of the baseare fixedterminals 17 and 18 held in place by screws extending through the wallofthe base from theunderside. The terminal piece 17 has a portion 21extending upwardly and inwardly to form a knife-blade contact. Piece 18has a similar portion 22 extending downwardly in the well in the baseand inwardly as shown in Fig. 2. At the other end of the base areterminals 23, 24 held in place by similar screws. These terminals areconnected by a portion 27 which lies in the well and has an oiisetportion forming a contact blade 28. Extending from the terminal piece 23inwardly and-upwardly,

in the same manner as does the blade '21, is 0 a contact blade 29. i j rv and in many cases also to attach a face pole tog le or =Each terminalpiece has a bindingscrew 30 for securing the lead wire. I l

The cover 12 is of molded insulating material and is hollow. At the endsof the cover are rojections, which engage the inner faces oft e bosses15, and shoulders which rest against the bosses 14. The cover has anaperture 31 for the thumb-piece and slots for the contact blades 21 and29.

The cover is clamped in position by ears 32 which serve also as a meansfor attaching the switch to a wall box, face plate or" other supportwhich commonl is used 'with switches of this type. Fort is latterurpose, the usual holes 33 are provided in t e oiiset attaching portions34 and are enlarged to permit some freedom of positioning. The cars?have oflsets or feet 35 which extend over the ledges 36 at the ends ofthe cover and thus, .when the ears are secured in position on the baseby the screws 37 which extend through holes from the underside of thebase, the cover is held tightly on the base. I

Attention is called to the fact that the 011'- sets 35 are bowed to givea certain resilience. This is to accommodate the slight differences indimfins ions of the cover 12 and of the lparts of the ase whichdetermine the relative evels of the ledges 36 and the tops of bosses 15.These diflerences are avoidable only at considerable expense inmanufacture but by the present construction are rendered immaterial. Theresilience of the bowed ofltsets also gives a tighter clamping actionandserves as a lock washer to keep the screws 37 from turning. It is tobe noted that the ears should be held flat against the boss 15 to as- 1sure proper positioning of the attaching ofisets .34 in the sameplane'parallel to that of the plate to which they are secured.

The switch movement may be of any desired form, the one shown here beinga double tumbler switch, more describe in my application referred toabove. It has a hand-rocked U-shaped lever which carries the thumb piece56 and is pivoted at its lower end on the down legs 44 of the double armmember 40 which extends lengthwise of the base; The frame 60 thatcarries the switch pieces 0 is pivoted on the under side of the Vaction.

double arm member and is connected to the rocking lever. by a spring 65which draws the frame upward against its fulcrum and the rocking lever50 downward against its fulcrum. When the thumb piece is moved, thelever 50 is rocked until the spring is carried beyond its dead centerposition, where The switch frame is set in the base well with the crossstraps 42 resting on the inner parts 15a of the bosses 15, these innerparts being at a lower level than the main parts, and

tensions 41 lie against the side faces of the main parts of the bosses.Thus the switch frame is held against both endwise and sidewise movementby reason of its relation to the bosses 15, straddling them as it doesboth from the top and from the side.

The cover 12 rests on the cross-pieces 42 and is of such dimensions thatwhen in position on the cross-pieces its rim just clears the top edge ofthe 'base. The clearance preferably 1s very slight and may be so slightas not to be noticeable to the eye. The important thing is to have thecover and base rims pressed together only at the two points where the Icover rests on, the cross-pieces and is clamped'by the ears 32. Thisgives a twooint mounting and prevents the strains that requently comeabout when a cover is held against a base all around its rim. If thecover were not used to hold a mechanism within the base, the sameprincipal could be employed by havinga clearance between the coverandobase rims except in the region of the" clamping members. I

The molding of the cover is greatly sim- I plified and made lessexpensive by-this arnee pressed down only at the rangement because ofthe facts that no care be taken to have the lbwer. rim of the coverandthe top rim of the base lie in a true plane, and that less materialis needed in the cover togive the necessary strength. It may happen thatthe clearance between the base rim and the cover rim will not be uniformat all points or that thereivill be a contact at some points, withoutappreciable pressure however, but thecover will be actually gages thecross pieces 42.

It will be observed that as the switch movepoints where it en-' on thebase, and an ear at each end of the base and secured thereto, each earhaving a portion engaging the cover to hold the latter on the base andanother portion for attaching the fittin to a support.

2. 11 electric fitting comprising a base, a cover of molded insulatingmaterial' resting on the base, an ear at each end of the base and.secured thereto, said ear having a bowed portion engaging the cover tohold the latter on the base and another portion for attaching thefitting to a support.

3. An electrical fitting comprising a base, a cover of molded insulatingmaterial for the base, a clamping member at each end of the base andsecured thereto, each clamping member having a portion engaging thecover to secure it to the base, the rim of the cover being adapted toclear therim of the base except in the region of said clamping member togive a two-point mounting.

4. An electric switch comprising a base,

-a Well therein, a switch movement in the Well,

said base having portions co-acting with portions of the switch movementto position the latter in the well, a cover of insulating materialengagin portions of said switch movement, an ear at each end of the baseand secured thereto, each ear having a portion engaging the cover tohold it and the switch movement portions against the base, and anotherportion for attaching the fitting to a support. r

5. An electric switch comprising a base, a well therein, a switchmovement in the well having a main frame resting on said base, a coverof molded insulating material secured to thebase and bearing on portionsof said frame to, hold the latter to the base, the rims of said coverandbase having a slight clear ance.

6.. An electric switch comprising a base with a well therein and bossesat its two ends extending above its top edge, a switch frame havingportions straddling said bosses to be held against all lateral movement,a cover of molded insulating material resting on por tions of said frameto hold the latter to the base, said cover and base not being pressedtogether at other points and means securing said cover to said base.

GEORGE JOHNSON.

ment is a unitary thing, all parts being car-J ried by the frame 40, itis held in the base-by the engagement of the cover" with the cross 'lgo

